If you haven't otherwise written anything sketchy or illegal on Medium then maybe you were blocked for one of these rules:
Cryptocurrency Accounts, Posts, and Publications
Posts and accounts that focus on cryptocurrencies which do not meet the following requirements may be considered spam and are subject to suspension, depending on context. Medium does not endorse or verify any coin, token, or similar announcement.
To prevent fraud and abuse, you must:
Include a link to your active project domain in your user account bio.
Use an email address from that domain as your verified Medium account email, and maintain that email account actively.
Link at least one consistently-branded social media account (Facebook or Twitter) to your Medium account. That social account should also link out prominently to the same domain as is included in your Medium user bio.
Include a prominent about page with up-to-date contact information on your project website.
You may not:
Use an anonymous email address which is not linked to your project domain (e.g., gmail, protonmail, mail.ru, etc.)
Advertise or participate in bounty campaigns, pump and dumps, reviewing for reward, or other forms of brigading or inauthentic activity
Include shortened URLs in your posts
